Single-cell characterization of the immune heterogeneity of pulmonary hypertension identifies novel targets for immunotherapy.

Abstract

Background: Pulmonary arterial hypertension (PAH) is a critical cardiopulmonary vascular disorder marked by the progressive elevation of pulmonary artery pressure, increased pulmonary vascular resistance, and eventual right heart failure. Research has shown that various immune cells play a significant role in the pathogenesis of PAH, both in patients diagnosed with the condition and in experimental models of PAH. Cell-cell communication is important for PAH progression and therapies, while the global cell landscape of intercellular signaling has not been elucidated.

Methods: We performed single-cell RNA sequencing on NCBI Gene Expression Omnibus (GEO) databases GSE169471, GSE 210248, GSE228643 and GSE244781, and analyzed lung tissue samples across healthy controls and PAH patients. In total, approximately 124,561 cells were analyzed and a total 34 clusters were identified. We integrated the sequencing results of multiple samples and used an enhanced single-cell sequencing workflow to overcome the limitations of a single study.

Results: In this study, we elucidated the functional characteristics and potential regulatory interactions of several cell subpopulations that have not been previously documented in similar research. We constructed a comprehensive landscape of cell communications at the single-cell resolution, which is expected to significantly advance the development of personalized diagnostic and therapeutic strategies for PAH. We demonstrated the transcriptomic features of different cell types in PAH patients. We presented an in-depth analysis of T cell subsets, myeloid cell heterogeneity and a comprehensive analysis of SMCs and FBs subsets in PAH. T cell heterogeneity and functional dynamics were exhibited in PAH, which suggests that targeting cytotoxic regulation may be a potential therapeutic strategy. Significant changes and potential functions of myeloid cell subsets in PAH patients and we especially focused on GPNMB⁺ macrophages. In addition, CellChat and NicheNet analyses reveal altered intercellular communication and dys-regulated signaling pathways in PAH progression. The enhanced MIF and IL-1 signaling suggests that the induced inflammatory response in PAH is greatly driven.

Conclusions: We systematically explored the immune heterogeneity and population and target cells in PAH, which may be valuable for developing new and precise therapies.